form {
  width: 80%;
  margin: 0 auto;
  min-width: 9rem;
}

input, textarea {
/*    float: left;*/
  width: 100%;
  max-width: 100%;
  border: 1px solid #e0e0e0;
  margin: 0.5rem 0;
  padding: 0.5rem 1rem;
  border-radius: 0.3rem;
/*  background: #e0e0e0;*/
  color: #7a7a7a;
}
input[type=submit], textarea[type=submit] {
  background: #13baa8;
  color: #fff;
  width: auto;
  float: right;
  display: block;
  text-decoration: none;
  letter-spacing: 0.1em;
  border-radius: 3px;
  padding: 0.3rem 2rem;
  box-shadow: 1px 2px 3px rgba(0,0,0,0.2);
  transition: 0.3s;
}
input::-moz-placeholder, textarea::-moz-placeholder {
  color: #7a7a7a;
}
input::placeholder, textarea::placeholder {
  color: #7a7a7a;
}
input.error, textarea.error {
  background: #AD4747;
  color: #fff;
}
input.error::-moz-placeholder, textarea.error::-moz-placeholder {
  color: black;
}
input.error::placeholder, textarea.error::placeholder {
  color: black;
}

textarea {
  height: 10rem;
}

* {
  box-sizing: border-box;
}